1. Field of the Invention
The present invention relates to processing signals. More particularly, the present invention relates to a device and method for processing communication signals.
2. Description of the Related Art
Unwanted noise is a problem in any communication. On Skype, for instance, communication between parties is often facilitated by concurrently typing messages with a keyboard and speaking through a microphone. Keyboard click noise is often picked up by the microphone and transmitted over to one's headphones or speakers. The noise usually intermixes with the voice and interferes with one's ability to decipher the voice message. The noise often makes the voice message unintelligible or indistinct. As such, keyboard click noise can be very annoying in any voice communication and it is highly desirable to remove this noise or at least to significantly minimize its level.
Unfortunately, it is a very challenging task to minimize the keyboard click noise since keyboard click noise is completely different from other noise sources. Conventional noise reduction schemes have not been successful. One conventional noise reduction scheme implements a band-stop filtering technique. But, this technique presents two problems: (1) cancellation of voice if it is at the same signal band as the keyboard click noise; and (2) output will include audible artifacts (sometimes, the artifacts level could be the same as that of the keyboard click noise level itself). These two problems highly prevent this technology and its products from being widely accepted by customers and from being practically used.
Accordingly, goals of the present invention include addressing the above problems by providing an effective keyboard click noise minimization scheme and its real-time implementation.